Manufacturing industries, such as mining and food preparation, often employ sorting/sifting tables to separate material based on size. The sorting tables typically uses a series of screens that are attached to a vibration frame. The frame imparts vibration to the screens to sift material placed on the screens. The size of openings provided in the screens determines the size of the material that is sorted through the screens.
The screens are typically attached to the frame in a manner that allows for a tension to be maintained between the screens and the frame, without rigidly attaching the components. As illustrated in FIG. 1, one type of fastener 100 that can be used to couple a screen 110 to a frame 120 comprises a shaft 102 having a fastening end 104 that can be coupled to the screen. The fastener can be attached using a bolt 108 or similar feature, such as a hook provided on the screen. The shaft 102 passes through the frame 120. A shoulder 112 can be provided on the shaft to contact the frame 120. The shaft 102 also passes through a first washer 114, a spring 116 and a second washer 118. The opposite end 106 of the shaft is threaded to accept a nut 122. The nut 122 is threaded onto the shaft 102 to compress the spring 116. This type of fastener couples the screen 110 to the frame 120 and allows some relative movement of the screen and frame to be absorbed by the spring 116. The screen can be removed by unthreading the nut and allowing the spring to expand. It will be appreciated that each screen uses multiple fasteners 100 on opposite sides of the screen.
The manufacturing environment in which the sorting equipment is operating can be excessively noisy. As such, the amount of time that employees are exposed to the high noise levels needs to be minimized. The above-described fastener requires that numerous nuts be un-threaded to remove or maintain a sorting screen. Other disadvantages of the prior threaded fastener include, bending or breaking the fastener shaft due to torque applied to the nut, and corrosion and dirt can prevent removal of the nut.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for a quick release tension fastener.